Bug 942290: Merge ARM exidx info with DWARF if both are present.
Bug 964427: Whitelist msync (asm.js cache) and sched_get_priority_m{in,ax} (webrtc).
Recognize SIGSYS as a crash
Sandbox: Fail by re-raising sigsys, not by _exit'ing.
Hook up the Sandbox SIGSYS handler to the crash reporter.
Bug 945504: Include JS stack in sandbox reporter logs.